DESCRIPTION (provided by investigator): Several viruses in the family Bunyaviridae are significant human pathogens and potential agents of bioterrorism. Vaccines against some of these viruses do exist, but with the exception of ribavarin, there are no broad-spectrum antiviral compounds capable of inhibiting replication of more than one member of the family. Using LaCrosse virus (LAC) as a prototype virus for the family, we plan to develop a combination of infection-dependent and infection-independent screening tools and to initiate a screen for compounds with anti-bunyavirus activity. The screening tools will be based on virus promoter-driven reporter gene constructs generated by bacteriophage T7 RNA polymerase or mammalian RNA polymerase I. Similar systems have been developed and utilized for other negative strand viruses including respiratory syncytial virus, Ebola virus, and influenza A virus. We plan to use the LAC infection-independent system in an automated, high throughput screening program to identify small molecule antiviral compounds. Compounds that exhibit antiviral activity will be tested for effectiveness against LAC-infected cells. Active compounds will then be assessed for broad-spectrum antiviral activity using virus promoter driven reporter genes derived from the bunyaviruses Hantaan (NIAID category A agent), Sin Nombre (NIAID category A agent), Rift Valley Fever (NIAID Category A agent) and Crimean Congo Hemorhagic Fever (NIAID category C agent). Given that LAC is a NIAID Category C agent completion of this application should identify antiviral compounds active against one and perhaps several NIAID priority pathogens. The combination of high throughput screening, rapid virus specific readouts of infectivity and available BSL2/BSL3 space make this application an attractive prototype for screening of broad spectrum antimicrobial compounds with other NIAID priority pathogens. [unreadable] [unreadable]